It is customary when fabricating electrically heated floors to connect the wire leads of the heating wires together by solder and then to position a shrinkable isolating sleeve over the soldered interconnection whereby to protect the connection and provide electrical insulation. Shrink sleeves are usually provided with an inside layer of hot glue and they are of a length of about 4 to 5 inches. A disadvantage with these is that one cannot warranty-that the placement of wires is fully secure. These isolating sleeves are required for every welded connection. Because these sleeves are flexible the welded connections and the entire assembly remain flexible which makes it more fragile and thus could lead to breakage or damage to the welded connection. The securement of these sleeves is also a time-consuming and inaccurate process. Air can also be trapped in these double wall construction shrink sleeves and this could eventually result in corrosion of the welded interconnection.
Further, often these insulating shrink sleeves do not form a perfect seal about the wires and this exposes the leads which are welded and permitting humidity infiltration into the soldered connection resulting in rust formation and affecting the conductivity of the wire or resulting in a wire breakage and short circuit. When a short circuit arises after the wires have been embedded in cured cement it is necessary to find the break in the wire and to then repair the connection. This often necessitates breaking ceramic floors which have been disposed over the cement and this is a time-consuming and expensive operation. Therefore, there is a need to provide connections which are well protected and entirely insulated form humidity and the ground.
Another disadvantage of the interconnection between such wires is that the welded connection and isolating sleeve is of irregular shape. These connections are also not resistant to impact and because these wires are usually installed by construction workers they are subject to all sorts of abuse caused by people walking over the connectors or subjecting the connectors to excessive shock. When setting the shrink sleeves about the connections, it results in a section of the wire having an unstable shape and therefore in order to make sure that these connections are embedded under the surface of the cement that is placed thereof, often it is necessary to make a cavity in the sub-floor and to secure the connection therein by glue or other means. A still further disadvantage of these prior art interconnections is that they are time-consuming to make and, therefore, expensive.